1. Field of the Invention
One example of the present invention relates to a semiconductor device, a display device, and the like.
2. Description of the Related Art
A shift register circuit formed using transistors having the same polarity has been actively developed these days (see Patent Document 1). The shift register circuit of Patent Document 1 uses n-channel transistors and, when a clock signal is brought into a high level, outputs the clock signal, thereby outputting high-level signals sequentially. However, because the shift register circuit of Patent Document 1 outputs a clock signal, low-level signals cannot be output sequentially.
Further, in the case where the shift register circuit of Patent Document 1 uses p-channel transistors, although low-level signals can be output sequentially, high-level signals cannot be output sequentially.